Hypothesis: The hypothesis to be tested is that Eticholandione is safe and well tolerated in patients with Prader Willi Syndrome and it decreases body weight in patients with this disorder. A. SPECIFIC AIMS: The aims of this study are: 1) To determine the dose and dosing schedule of etiocholanolone that will restore etiocholanolone levels in subjects with Prader-Willi syndrome (PWS) to those found in normal individuals. 2) To determine the safety of this dose with regard to adverse events, laboratory parameters, and social and family functioning over a two week period. 3) To determine the safety and efficacy of etiocholandione given in the manner developed in Steps 1 and 2 in promoting weight loss in patients with PWS over a 3 month period. The long term goal of this project is to develop the preliminary data necessary to obtain FDA approval for a longer Phase III study involving a larger group of PWS patients.